The invention relates to sheet drying apparatus in general, and more particularly to improvements in apparatus for drying short or long series of successive sheets which are transported by a conveyor through one or more drying stations. Still more particularly, the invention relates to improvements in sheet drying apparatus of the type wherein the sheets are transported by a foraminous conveyor to advance above a stationary heating device and a stationary suction chamber.
Sheet heating apparatus which employ a foraminous conveyor, a stationary heating device and a stationary suction chamber are disclosed in commonly owned U.S. Pat. No. 4,619,050 granted Oct. 28, 1986 to Klemm and in German Pat. No. 26 07 504. The patented apparatus can be utilized with advantage to reduce the moisture content of sheets which issue from a printing machine, e.g., a screen printing machine. A drawback of presently known sheet drying apparatus is that they cannot satisfactorily treat moisture-containing sheets which issue from a high-speed printing machine. Moreover, presently known sheet drying apparatus are not sufficiently accident proof to meet the safety rules and regulations in certain countries. Still further, presently known drying apparatus cannot invariably reduce the moisture content of sheets in such a way that the quality of the dried products is not affected by the drying action, especially if the sheets are to be dried at a high or very high frequency.